Conventional devices for sensing sonic, subsonic and ultrasonic acoustic waves in a fluid medium, i.e. liquid or gas, include piezoelectric materials, ferroelectric ceramics, fiber optic sensors, electromagnetic (moving coil) sensors, condenser and electret sensors and magnetostrictive transducers. Such devices are difficult to miniaturize and/or use materials which are incompatible with silicon processing and so may not be fabricated using silicon chip technology. At best, a hybrid device can be achieved. Further, implementation on an integrated circuit chip is not practical. The devices are typically fabricated using discrete elements which are relatively large and expensive to make and cannot generally be integrated with the electronics on a single chip. The cabling required for electrical connection between the discrete elements, e.g. transducer and buffer electronics introduces stray capacitance and attendant noise. These devices are also sensitive to acceleration forces and subject to substantial low-frequency (1/f) noise from the buffer electronics. Certain of these devices, including the ferroelectric ceramic devices, show under the influence of time, pressure and temperature.